unapproachable
Seeming unfriendly or scary so people don’t want to talk.
Someone who is unapproachable seems distant, unfriendly, or intimidating in a way that makes others reluctant to talk to them or ask them questions. An unapproachable teacher might frown and seem annoyed whenever students raise their hands, making the class afraid to speak up even when they need help. An unapproachable kid at school might always look angry or bored, so other students feel nervous about trying to make friends.
The word describes how someone appears to others, not necessarily how they actually feel inside. Someone might seem unapproachable because they're shy or deep in thought, not because they genuinely want to push people away. A new principal might seem unapproachable at first simply because students don't know her yet.
The opposite quality is being approachable, which means seeming warm, open, and easy to talk to. Approachable people make eye contact, smile, and show interest when others speak to them. When someone is unapproachable, they can create an invisible barrier that keeps others at a distance, even if they don't mean to.